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United States Patent |
5,660,788
|
Gray
,   et al.
|
August 26, 1997
|
Process for forming a apertured, three-dimensional, macroscopically
expanded, plastic web for absorbent articles having a textured
wearer-contacting surface
Abstract
A fluid pervious topsheet suitable for use on an absorbent article is
disclosed. The topsheet includes an apertured, three-dimensional,
macroscopically expanded, fluid pervious web having a textured
wearer-contacting surface. The composite web permits liquids to penetrate
while providing an improved, less plastic-like feel and visual aesthetics.
The process of the present invention, in one embodiment, comprises
extruding a polymeric film onto a forming structure, applying a pneumatic
pressure to the film to cause the film to be urged into substantial
conformance with the forming structure, and depositing a particulate
material on said film while the film is in a semi-molten state. In another
embodiment, the process of the present invention comprises extruding a
polymeric film onto a forming structure, depositing a particulate material
on the film while the film is in a semi-molten state to form a composite
web, and applying a pneumatic pressure to the film to cause the film to be
urged into substantial conformance with the forming structure.
Inventors:
|
Gray; Brian F. (Burlington, CA);
Schettler; Michael J. (Barrie, CA);
Ashton; Gregory (Markham, CA)
|
Assignee:
|
The Procter & Gamble Company (Cincinnati, OH)
|
Appl. No.:
|
478077 |
Filed:
|
June 7, 1995 |
Current U.S. Class: |
264/504; 427/180 |
Intern'l Class: |
B29C 067/00 |
Field of Search: |
264/504,131,156
425/290,387.1,388
156/62.2,252,253,308.2,309.9
428/131,137
427/180,197,198
|
References Cited
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3165432 | Jan., 1965 | Plaskett | 156/244.
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3190781 | Jun., 1965 | Metz, Jr. | 156/244.
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3331728 | Jul., 1967 | Lane | 161/112.
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3421964 | Jan., 1969 | Arbit | 156/244.
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3523149 | Aug., 1970 | Hartmann | 264/90.
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3878014 | Apr., 1975 | Melead | 156/167.
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3881488 | May., 1975 | Delanty et al. | 128/287.
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3911186 | Oct., 1975 | Trotman | 428/137.
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3917501 | Nov., 1975 | Ferrucci et al. | 264/131.
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3929135 | Dec., 1975 | Thompson | 128/287.
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3945386 | Mar., 1976 | Anczurowski et al. | 128/287.
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3965906 | Jun., 1976 | Karami | 128/287.
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3967623 | Jul., 1976 | Butterworth et al. | 128/287.
|
3987792 | Oct., 1976 | Hernandez et al. | 128/284.
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3994299 | Nov., 1976 | Karami | 128/287.
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4077410 | Mar., 1978 | Butterworth et al. | 128/287.
|
4323069 | Apr., 1982 | Ahr et al. | 128/287.
|
4342314 | Aug., 1982 | Radel et al. | 128/287.
|
4463045 | Jul., 1984 | Ahr | 604/370.
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4609518 | Sep., 1986 | Curro et al. | 264/504.
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4619724 | Oct., 1986 | Chatow | 156/72.
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4622036 | Nov., 1986 | Goodrum | 604/367.
|
4695422 | Sep., 1987 | Curro et al. | 264/504.
|
4726976 | Feb., 1988 | Karami et al. | 428/137.
|
4741877 | May., 1988 | Mullane, Jr. | 264/504.
|
4747991 | May., 1988 | Bishop | 264/504.
|
4781962 | Nov., 1988 | Zamarripa et al. | 428/138.
|
4797246 | Jan., 1989 | Reinke et al. | 264/504.
|
4878825 | Nov., 1989 | Mullane, Jr. | 264/504.
|
4985023 | Jan., 1991 | Blank et al. | 604/360.
|
4995930 | Feb., 1991 | Merz et al. | 156/209.
|
5019062 | May., 1991 | Ryan et al. | 604/359.
|
5171238 | Dec., 1992 | Kajander | 604/383.
|
5173351 | Dec., 1992 | Ruppel et al. | 428/1.
|
5282915 | Feb., 1994 | Westlake, Jr. | 156/243.
|
5368909 | Nov., 1994 | Langdon et al. | 428/137.
|
5368910 | Nov., 1994 | Langdon | 428/137.
|
5383870 | Jan., 1995 | Takai et al. | 604/366.
|
5387209 | Feb., 1995 | Yamamoto et al. | 604/366.
|
5514308 | May., 1996 | Cohen et al. | 156/308.
|
Foreign Patent Documents |
0 018684 | Nov., 1980 | EP.
| |
0 018 684 | Nov., 1980 | EP.
| |
0 040 084 | Nov., 1981 | EP | .
|
0 295 694 | Dec., 1988 | EP | .
|
0 409 535 A1 | Jan., 1991 | EP | .
|
0 545 423 A1 | Jun., 1993 | EP | .
|
57-191022 | Nov., 1982 | JP | 264/131.
|
2-193663 | Jul., 1990 | JP | .
|
4-152945 | May., 1992 | JP | .
|
5-137752 | Jun., 1993 | JP | .
|
982757 | Feb., 1965 | GB.
| |
WO93/09741 | May., 1993 | WO | .
|
WO93/12749 | Jul., 1993 | WO.
| |
WO93/22995 | Nov., 1993 | WO | .
|
WO94/24354 | Nov., 1994 | WO.
| |
Primary Examiner: Timm; Catherine
Attorney, Agent or Firm: Johnson; Kevin C., Andes; William Scott, Linman; E. Kelly
Parent Case Text
CROSS REFERENCE TO RELATED APPLICATION
This application is a division of application Ser. No. 08/154,661, filed on
Nov. 18, 1993.
Claims
What is claimed:
1. A process for forming an apertured, three-dimensional macroscopically
expanded web, said process comprising the steps of:
(a) extruding a polymeric film onto a forming structure, said forming
structure exhibiting a macroscopic, three-dimensional, cross-section
defined by a multiplicity of macroscopic apertures which place opposed
surfaces of said forming structure in fluid communication with one
another;
(b) applying a pneumatic pressure to said film to cause said film to be
urged into substantial conformance with the macroscopic three-dimensional,
cross-section of said forming structure forming a three-dimensional,
macroscopically expanded, formed web having first and second surfaces
located in planes remote from one another, said formed web having a
plurality of capillaries extending from said first surface to said second
surface, said capillaries being defined by a plurality of sidewall
portions interconnected to one another intermediate said first and second
surfaces and terminating in said second surface; and
(c) depositing a particulate material onto said first surface of said
formed web and into said capillaries of said formed web along said
sidewall portions while said formed web is in a semi-molten state, such
that said particulate material is secured to said first surface and said
sidewall portions of said formed web, wherein said particulate material is
talc.
Description
FIELD OF THE INVENTION
The present invention relates to absorbent articles such as sanitary
napkins, pantiliners, disposal diapers, incontinent articles, and the
like, and more particularly, the present invention relates to absorbent
articles having an apertured, three-dimensional, macroscopically expanded,
plastic web topsheet, the wearer contacting surface of which is textured.
BACKGROUND OF THE INVENTION
All manner and variety of absorbent articles configured for the absorption
of bodily fluids are, of course, well known. Current types of absorbent
articles include sanitary napkins, pantiliners, disposable diapers, and
incontinent articles.
Macroscopically expanded, three-dimensional, apertured, films have been
used as topsheets on such absorbent articles. As used herein, the term
"macroscopically expanded", when used to describe three-dimensional,
plastic webs, ribbons and films, refers to webs, ribbons and films, which
have been caused to conform to the surface of a three-dimensional forming
structure so that both surfaces thereof exhibit the three-dimensional
pattern of the forming structure, the pattern being readily visible to the
naked eye when the perpendicular distance between the viewer's eye and the
plane of the web is about 12 inches.
One macroscopically expanded, three-dimensional, apertured plastic web
which is particularly well suited to transferring fluid deposited on one
surface thereof to its opposite surface and thereafter isolating the
transferred fluid from the wearer's skin is disclosed in commonly assigned
U.S. Pat. No. 3,929,135 issued to Thompson on Dec. 30, 1975, and hereby
incorporated herein by reference. Thompson describes a macroscopically
expanded, three-dimensional, topsheet comprised of liquid impermeable
material, but provided with a pattern of tapered capillaries, the
capillaries have a base opening in the plane of the topsheet contacting
the wearer's body and an apex opening remote from the base opening of the
topsheet, the apex opening being in intimate contact with the absorbent
pad utilized in the disposable absorbent article. The Thompson topsheet
allows for the free transfer of fluid from the wearer's body into the
absorbent element of the device while inhibiting the reverse flow of these
fluids. This provides a relatively much dryer surface in contact with the
user than had previously been obtainable.
Another macroscopically expanded, three-dimensional, apertured plastic web
well suited for use as a topsheet on absorbent articles such as sanitary
napkins is disclosed in commonly assigned U.S. Pat. No. 4,342,314 issued
to Radel et al. on Aug. 3, 1982, said patent being hereby incorporated
herein by reference. The macroscopically expanded, three-dimensional
plastic web disclosed in the Radel et al. patent exhibits a fiber-like
appearance and tactile impression which has been favorably received by
consumers when used as a wearer contacting surface.
While macroscopically expanded, three-dimensional, apertured plastic webs
have achieved widespread commercial success when employed as topsheets on
absorbent articles, some users are very reluctant to place a topsheet
which they readily perceive as plastic in contact with their skin.
Accordingly, it is therefore an object of the present invention to provide
a topsheet for an absorbent article having fluid handling characteristics
comparable to those found in macroscopically expanded, three-dimensional,
apertured plastic topsheets and an improved softer, less plastic-like look
and feel.
SUMMARY OF THE INVENTION
The present invention relates to absorbent articles such as diapers,
incontinent articles, sanitary napkins, and the like. More particularly,
this invention relates to absorbent articles having a resilient,
three-dimensional, macroscopically expanded, fluid pervious plastic web.
The plastic web has a first surface and a second surfaces located in
planes remote from one another. At least a portion of the first surface of
the web has a particulate material secured thereto. The web includes a
plurality of capillaries extending from the first surface to the second
surface of the web. The capillaries are defined by a plurality of sidewall
portions interconnected to one another intermediate the first and second
surfaces of the web. The sidewall portions terminate in the second surface
of the web. In a preferred embodiment, the sidewall portions also have a
particulate material secured thereto. Preferably, the particulate material
is talc.
The present invention also provides a process for forming an apertured,
three-dimensional, macroscopically expanded web. A polymeric film is
extruded onto a forming structure. The forming structure exhibits a
macroscopic, three-dimensional, cross-section defined by a multiplicity of
macroscopic apertures which place the opposed surface of the forming
structure in fluid communication with one another. A pneumatic pressure is
applied to the film to cause the film to be urged into substantially
conformance with the macroscopic, three-dimensional, cross-section of the
forming structure thereby forming a three-dimensional, macroscopically
expanded formed web having first and second surfaces located in planes
remote from one another. The formed web has a plurality of capillaries
extending from the first surface to the second surface. The capillaries
are defined by a plurality of sidewall portions interconnected to one
another intermediate the first and second surfaces and terminate in the
second surface. A particulate material, preferably talc, is then deposited
on the film while the film is in a semi-molten state.
Alternatively, the particulate material may be applied to the web after it
has been extruded, but prior to passing over the vacuum chamber.
BRIEF DESCRIPTION OF THE DRAWINGS
While the specification concludes with claims particularly pointing out and
distinctly claiming the present invention, it is believed that the present
invention will be better understood from the following description in
conjunction with the accompanying drawings in which:
FIG. 1 is a simplified perspective view of an absorbent article of the
present invention;
FIG. 2 is a cross-sectional view taken along section line 2--2 of FIG. 1;
FIG. 3 is a cross-sectional view taken along section line 3--3 of FIG. 1;
FIG. 4 is an enlarged, partially segmented, perspective illustration of a
prior art plastic web of the type generally enclosed in commonly assigned
U.S. Pat. No. 4,342,314;
FIG. 5 is a photograph enlarged approximately 27 times of a preferred
embodiment of an apertured, macroscopically expanded, three-dimensional,
plastic web having a textured wearer-contacting surface of the present
invention, the photograph being taken from the wearer-contacting surface
of the web;
FIG. 6 is a simplified schematic representation of a process for making the
apertured, macroscopically expanded, three-dimensional, plastic web having
a textured wearer-contacting surface of the present invention; and
FIG. 7 is a greatly enlarged fragmentary illustration of a forming
structure which may be utilized to support the web of the present
invention in accordance with the process illustrated in FIG. 6.
DETAILED DESCRIPTION OF THE PRESENT INVENTION
The term "absorbent article", as used herein, refers to articles which
absorb and contain body exudates. More specifically, the term refers to
articles which are placed against or in proximity to the body of the
wearer to absorb and contain the various exudates discharged from the
body. The term "absorbent article:" is intended to include diapers,
incontinent articles, sanitary napkins, pantiliners, and other articles
used to absorb body exudates. The term "disposable " is used herein to
describe absorbent articles which are not intended to be laundered or
otherwise restored or reused as an absorbent article, i.e., they are
intended to be discard after a single use, and, preferably to be recycled,
composted or otherwise disposed of in an environmentally compatible
manner.
The term "diaper" refers to a garment generally worn by infants and
incontinent persons which is worn about the lower torso of the wearer.
Suitable diapers that can be provided with the topsheet described herein
are disclosed in U.S. Pat. No. Re. 26,152, issued to Duncan, et al. on
Jan. 31, 1967; U.S. Pat. No. 3,860,003 issued to Buell on Jan. 14, 1975;
U.S. Pat. No. 4,610,678 issued to Weisman, et al. on Sep. 9, 1986, U.S.
Pat. No. 4,673,402 issued to Weisman, et al. on Jun. 16, 1987; U.S. Pat.
No. 4,695,278 issued to Lawson on Sep. 22, 1987; U.S. Pat. No. 4,704,115
issued to Buell on Nov. 3, 1987; U.S. Pat. No. 4,834,735 issued to Alemany
et al. on May 30, 1989; U.S. Pat. No. 4,888,231 issued to Angstadt on Dec.
19, 1989; and U.S. Pat. No. 4, 909,803 issued to Aziz, et al. on Mar. 20,
1990; each of which is incorporated herein by reference.
The term "incontinent article" refers to pads, undergarments (pads held in
place by a suspension system of some type, such as a belt, or the like),
inserts for absorbent articles, capacity boosters for absorbent articles,
briefs, bed pads, and the like, regardless of whether they are worn by
adults or other incontinent persons. Suitable incontinent articles that
can be provided with the topsheet described herein are disclosed in U.S.
Pat. No. 4,253,461 issued to Strickland, et al. on Mar. 3, 1981; U.S. Pat.
Nos. 4,597,760 and 4,597,761 issued to Buell; the above-mentioned U.S. Pat
No. 4,704, 115; U.S. Pat. No. 4,909,802 issued to Ahr, et al.; and U.S.
Pat. No. 4,964,860 issued to Gipson, et al. on Oct. 23, 1990; each of
which is incorporated herein by reference. The term "sanitary napkin"
refers to an article which is worn by females adjacent to the pudendal
region that is intended to absorb and contain various exudates which are
discharged from the body (e.g., blood, menses and urine). Suitable
sanitary napkins that can be provided with the topsheet described herein
are disclosed in U.S. Pat. No. 4,285,343, issued to McNair on Aug. 25,
1981; U.S. Pat. Nos. 4,589, 876 and 4,687,478 issued to Van Tilburg on May
20, 1986 and Aug. 18, 1987 respectively; U.S Pat. Nos. 4,917,697 and
5,007,906 issued to Osborn, et al. on Apr. 17, 1990 and Apr. 16, 1991,
respectively; and U.S. Pat. Nos. 4,950,264 and 5,009,653 issued to Osborn
on Aug. 21, 1990 and Apr. 23, 1991,respectively; each of which is
incorporated herein by reference. The term "pantiliner" refers to
absorbent articles that are less bulky than sanitary napkins which are
generally worn by women between their menstrual periods. Suitable
pantiliners that can be provided with the topsheet described herein are
disclosed in U.S. Pat. No. 4,738,676 issued to Osborn on Apr. 19, 1988.
FIG. 1 shows a simplified absorbent article 10 that could represent a
diaper prior to its being placed on a wearer. It should be understood,
however, that the present invention is not limited to the particular type
or configuration of absorbent article shown in the drawings. As shown in
FIG. 2, such an absorbent article 10 basically comprises a topsheet 12, a
backsheet 14, and an absorbent core 16.
The absorbent article 10 has two surfaces, a body-contacting surface (or
"body surface") 10a and a garment surface 10b. The body surface 10a is
intended to be worn adjacent to the body of the wearer. The garment
surface 10b of the absorbent article 10 (shown in FIG. 2) is on the
opposite side and is intended to be placed adjacent to the wearer's
undergarments or clothing when the absorbent article 10 is worn.
The absorbent article 10 has two centerlines, a longitudinal centerline 1
and a transverse centerline t. The term "longitudinal", as used herein,
refers to a line, axis or direction in the plane of the absorbent article
10 that is generally aligned with (e.g., approximately parallel to) a
vertical plane which bisects a standing wearer into left and right body
halves when the absorbent article 10 is worn. The terms "transverse" or
"lateral" as used herein, are interchangeable, and refer to a line, axis
or direction which lies within the plane of the absorbent article 10 that
is general perpendicular to the longitudinal direction. FIG. 1 shows that
the absorbent article 10 has two spaced apart longitudinal edges 18 and
two spaced apart transverse or end edges (or "ends") 20, which together
form the periphery 22 of the absorbent article 10.
The topsheet 12 is compliant, sofa-feeling and non-irritating to the
wearer's skin. Further, topsheet 12 is liquid permeable, permitting
liquids to readily penetrate through its thickness. The topsheet 12 has a
body-facing side or face 12a and a garment-facing side or face 12b, two
longitudinal or side edges . 12c and two end edges 12d. (A similar
numbering system will be used for the other components of the diaper 10.
That is, the side of the component facing the wearer's body will be
designated by the number of the component and a reference letter "a", the
side facing the wearer's undergarments by the number of the component and
the letter "b", and the side and end edges by the number of the component
and the reference letters "c" and "d" respectively.)
FIG. 4 is an enlarged, partially segmented, perspective illustration of a
prior art macroscopically expanded, three-dimensional, fiber-like,
apertured, plastic film 26 which has been found highly suitable for use as
a topsheet in disposal absorbent articles. Prior art plastic film 26 is
generally in accordance with the teachings of commonly assigned U.S. Pat.
No. 4,342,314 issued to Radel, et al. on Aug. 3, 1982 and is hereby
incorporated herein by reference. The plastic film 26 exhibits a
multiplicity of apertures, e.g., apertures 31, which are formed by a
multiplicity of intersecting fiber-like elements, e.g., elements 32, 33,
34, 35 and 36 interconnected to one another in the first surface 40 of the
web. Each fiber-like element comprises a base portion, e.g., base portion
41 located in plane 42. Each base portion has a sidewall portion, e.g.,
sidewall portions 43, attached to each edge thereof. The sidewall potions
extend generally in the direction of a second surface 45 of the web. The
intersecting sidewall portions of the fiber-like elements are
interconnected to one another immediate the first and second surfaces of
the web, and terminate substantially concurrently with one another in the
plane 46 of the second surface to form apetures 39 in the second surface
45 of the web. The capillaries 49 formed by the interconnected sidewall
portions allows for free transfer of fluid from the first surface of the
web directly to the second surface of the web without lateral transmission
of the fluid between the adjacent capillaries.
The apertured plastic film 26 is manufactured from a liquid impervious,
preferably thermoplastic material. The thermoplastic material for use in
the manufacture of the apertured formed plastic film 26 is selected from a
group generally consisting of polyethylene, polypropylene, polyvinyl
chloride, starch base resins, polyvinyl alcohol, polyurethanes,
polycaprolactone cellulose esters and blends thereof.
Examples of other macroscopically expanded, three-dimensional, apertured,
plastic webs are disclosed in U.S. Pat. No. 3,939,135 issued to Thompson
on Dec. 30, 1975; U.S. Pat. No. 4,324,426, issued to Mullane, et al. on
Apr. 13, 1982; and U.S. Pat. No. 4,463,045, issued to Ahr, et al on Jul.
31, 1984; each of said patents being hereby incorporated herein by
reference.
FIG. 5 is a photograph of an apertured, macroscopically expanded,
three-dimensional, plastic web having a textured wearer-contacting
surface, generally indicated as 100. Web 100 is particularly well suited
for use as a topsheet, e.g., topsheet 12 illustrated in FIG. 1, on an
absorbent article such as a diaper or sanitary napkin. The apertured,
macroscopically expanded, three-dimensional, plastic web is generally in
accordance with the teachings of commonly assigned U.S. Pat. No. 4,342,314
issued to Radel et al. The web 100 exhibits a multiplicity of apertures,
e.g., apertures 131, which are formed by a multiplicity of intersecting
fiber-like elements, e.g., elements 132, 133, 134, and 135 interconnected
to one another in the first surface of the web. Each fiber-like element
comprises a base portion located in the uppermost or wearer-contacting
plane. Each base portion has a sidewall portion attached to each edge
thereof. The sidewall portions extend generally in the directed of a
second or absorbent core contacting surface of the web. The intersecting
sidewall portions of the fiber-like elements are interconnected to one
another intermediate the first and second surfaces of the web, and
terminate substantially concurrently with one another in the plane of the
second surface to form apertures in the second surface of the Web. The
capillaries 140 formed by the interconnected sidewall portions allow for
free transfer of fluid from the first of wearer-contacting surface of the
web directly to the second or absorbent core contacting surface of the web
without lateral transmission of fluid between adjacent capillaries.
Web 100 includes a particulate material 102 embedded on the
wearer-contacting surface of the web and along the sidewall portions of
the web. In a preferred embodiment the particulate material is talc.
Another suitable particulate material is clay.
Preferably, the size of the particulate material 102 is such that light
incident upon the visible surface of the web is substantially diffused
into a multiplicity of directions by the particulate material into a
multiplicity of directions rather than being speculary reflected, thereby
providing a non-glossy visible surface.
Web 100 exhibits a soft, wearer-contacting surface which is not slick,
sticky, or plastic-like when compared to prior art plastic films. The
addition of the particulate material 102 to the first or wearer contacting
surface of the apertured plastic film provides a textured surface which
when utilized as a topsheet on an absorbent article is in contact with the
wearer's skin. The addition of the particulate material to the wearer
contacting surface of the apertured plastic film reduces the plastic,like
feel often associated with such films which some users resist placing in
contact with their skin.
In a particularly preferred embodiment, the particulate material is present
when initially contacted by the wearer's skin in use. However, the
particulate material is then "washed away" by the introduction of fluids
(urine, menses, etc.). Therefore, the web 100 initially exhibits a sol,
clothlike visual and tactile impression while presenting the after-use
clean and dry benefits of prior art macroscopically expanded,
three-dimensional, plastic webs. Depending on the desired results, the
particulate material may be secured to the plastic web such that the
particulate material is not "washed away" by the introduction of fluids.
A suitable process of preparing the web 100 of the present invention is
shown in FIG. 6. In the embodiment shown in FIG. 6, a web of molten resin
200 is extruded from a conventional extruder 201 onto the surface of a
forming drum 205 about which a forming structure 210 rotates. The forming
drum 205 preferably includes an internally located vacuum chamber 220
which is preferably stationary relative to the moving forming structure
210. As the molten resin 200 passes across vacuum chamber 220 a pneumatic
pressure is applied to the molten resin to cause the resin to be urged
into substantial conformance with the forming structure 210. The
macroscopic cross-section of forming structure 210 is visible in the
greatly enlarged fragmentary perspective illustration of FIG. 7. Methods
of constructing a suitable three-dimensional tubular forming member
similar to that illustrated in FIG. 7 are disclosed in commonly assigned
U.S. Pat. No. 4,508,256 issued to Radel et al. on Apr. 2, 1985 and
commonly assigned U.S. Pat. No. 4,509,908 issued to Mullane, Jr. on Apr.
9, 1985, said patents being hereby incorporated herein by reference.
As the web of resin material conforms with the macroscopic cross-section of
forming structure 210 a three-dimensional, macroscopically expanded,
apertured web is created similar to that illustrated in FIG. 4. The web
has a first surface and a second surface. The formed web includes a
plurality of capillaries which extend from the first surface to the second
surface. The capillaries are defined by a plurality of sidewall portions
interconnected to one another intermediate the first and second surfaces
and which terminate in the second surface of the web.
After having been formed by vacuum chamber 220, a particulate material 206
is applied to the semi-molten resin from applicator 205. The particulate
material 206, preferably talc, readily adheres to the semi-molten resin to
produce a web similar to that shown in FIG. 5.
After the particulate material has been secured to the apertured, plastic
web, the resultant apertured, macroscopically expanded, three-dimensional,
plastic web having a textured wearer-contacting surface 208 is removed
from forming drum 210 by way of nip roll 225. The composite web 208 may be
fed to a rewind station for temporary storage or may be utilized without
further processing as a topsheet in an absorbent article.
Another suitable process for preparing the web 100 is by applying the
particulate material to the extruded web of molten resin prior to the web
crossing the vacuum chamber 220.
Yet, another suitable process for preparing the topsheet web 100 is by
reheating a previously formed macroscopically expanded, three-dimensional,
plastic web, to a semi-molten state prior to removing the web from the
forming drum 205, such that the particulate material may be secured to the
web.
The absorbent core 16 is positioned between the topsheet 12 and the
backsheet 14. The absorbent core 16 may be any absorbent means which is
capable of absorbing or retaining liquids (e.g.; menses and/or urine). As
shown in FIGS. 1-3, the absorbent core 16 has a body surface, a garment
surface, side edges and end edges. The absorbent core 16 may be
manufactured in a wide variety of sizes and shapes (e.g., rectangular,
oval, hour glass, dog bone, asymmetric, etc.) and from a wide variety of
liquid-absorbent commonly used in absorbent articles such as comminuted
wood pulp which is generally referred to as airfelt. Examples of other
suitable materials include creped cellulose wadding, cross-linked
cellulose fibers, absorbent foams, absorbent sponges, synthetic staple
fibers, polymeric fibers, hydrogel-forming polymer gelling agents, peat
moss, combinations of the foregoing, or any equivalent material or
combinations of materials. The configuration and construction of the
absorbent core may also be varied (e.g., the absorbent core may have
varying caliber zones (e.g., profiled so as to be thicker in the center)
hydrophilic gradients, super absorbent gradients, or lower density and
lower average basis weight acquisition zones); or may comprise one or more
layers or structures. The total absorbent capacity of the absorbent core
should, however, be compatible with the desired loading and the intended
use of the absorbent article. Further, the size and absorbent capacity of
the absorbent core may be varied to accommodate different uses such as
incontinence pads, pantiliners, regular sanitary napkins, or overnight
sanitary napkins.
Suitable cross-linked cellulose fibers are described in U.S. Pat. No.
4,888,093, issued to Cook, et al. on Dec. 19, 1989; U.S. Pat. No.
4,822,543, issued to Dean, et al. on Apr. 18, 1989; U.S. Pat. No.
4,889,595, issued to Schoggen, et al. on Dec. 26, 1989; U.S. Pat. No.
4,889,596, issued to Schoggen, et al. on Dec. 26, 1989; U.S. Pat. No.
4,898,642 issued to Moore, et al. on Feb. 6, 1990; U.S. Pat. No.
4,935,022, issued to Lash, et al. on Jun. 19, 1990.
The characteristics of the absorbent core 16 for particular types of
absorbent articles are described in greater detail in the patents and
documents incorporated by reference herein, and the patents and other
documents incorporated by reference herein. Other suitable absorbent core
arrangements are described in U.S. Pat. Nos. 4,988,344 and 4,988,345, and
European Patent Application Publication No. 0 198 683, published Oct. 22,
1986 in the name of Duenk, et al. which are also incorporated by reference
herein. The absorbent article could also include any additional layers or
other components such as are described in the patents incorporated by
reference. For example, the absorbent article 10 may comprise an
acquisition layer or patch or cross-linked cellulose fibers positioned
between the topsheet 12 and the absorbent core 16.
The backsheet 14 and the topsheet 12 are positioned adjacent to the garment
surface and the body surface, respectively, of the absorbent core 16 and
are preferably joined thereto and to each other by attachment means (not
shown) such as those well known in the art. For example, the backsheet 14
and/or the topsheet 12 may be secured to the absorbent core 16 by a
uniform continuous layer of adhesive, a patterned layer of adhesive, or an
array of separate lines, spirals, spots of adhesive, or meltblown
adhesives. Adhesives which have been found to be satisfactory are
manufacture by HB Fuller Company of St. Paul, Minnesota under the
designation HL-1258. The attachment means will preferably comprise an open
pattern network of filaments of adhesives as is disclosed in U.S. Pat. No.
4,573,986 issued to Minetola et al. on Mar. 4, 1986, and which is
incorporated herein by reference. An exemplary attachment means of an open
pattern network of filaments comprises several lines of adhesive filaments
swirled into a spiral pattern such as illustrated by the apparatus and
method shown in U.S. Pat. No. 3,91 1, 173 issued to Sprague, Jr. on Oct.
7, 1975; U.S. Pat. No. 4,785,996 issued to Zieker et al. on Nov. 22, 1978;
and U.S. Pat. No. 4,842,666 issued to Werenicz on Jun. 27, 1989. Each of
the patents are incorporated herein by reference. Alternatively, the
attachment means may comprise heat bonds, pressure bonds, ultrasonic
bonds, dynamic mechanical bonds, or any other suitable attachment means or
combinations of these attachment means as are known in the art.
The backsheet 14 is impervious to liquids and is preferably manufactured
from a thin plastic film, although other flexible liquid impervious
materials may also be used. The backsheet 14 prevents liquid contained in
absorbent core 16 from wetting articles which contact the absorbent
article 10. Polyethylene films having a thickness of from about 0.001 to
about 0.002 inches (0.0025 to 0.0051 cm.) have been used for the backsheet
14 with satisfactory results. As used herein, the term "flexible" refers
to materials which are compliant and which will readily conform to the
general shape and contours of the human body.
The backsheet 14 is superimposed on the garment-facing side 16b of
absorbent core 16 and preferably extends beyond the edges thereof. The
topsheet 12 is superimposed over the body-facing side 16a of the absorbent
core 16, and may also extend beyond the edges of the core 16. The
absorbent core 16 is, therefore, positioned between the topsheet 12 and
the backsheet 14. The topsheet 12 and backsheet 14 are joined to each
other such as around their peripheries. The topsheet 12 and backsheet 14
can be joined in any suitable manner such as by the use of adhesives,
crimping, heat-sealing, or ultrasonic bonding.
While a number of particularly preferred embodiments in the present
invention have been illustrated and described, it will be obvious to those
skilled in the art that various changes and modifications can be made
without the departing from the spirit and scope of the invention, and it
is intended to the appended claims all such modifications that are in the
scope of this invention.
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